Selectively vapor-permeable membrane heat sinks comprising a tungsten-containing contact plate and methods for manufacturing and using the same

Abstract

Disclosed are dual-phase heat sinks using vapor-permeable membrane(s) to reach unprecedented heat transfer coefficient and waste heat temperature recovery levels. A vapor-permeable membrane is sealed between a liquid region and a vapor region to allow only vapor-phase heat exchange fluid to pass from liquid region to vapor region. Vapor-permeable membranes can function as a mass controller, permitting the entry of liquid phase heat exchange fluid into heat sink in equilibrium with vapor phase heat exchange fluid being communicated through the vapor-permeable membrane. Reduced pressure drop across heat sink enables operation under hydrostatic pressure. A heat sink can comprise a thin tungsten-containing base between a contact surface and a heat source (e.g., chip) that improves stress distribution through heat sink and chip package, reduces mechanical strain from thermal stress, and increases durability of the assembly.

1 . A method comprising:
 coupling a top surface surrounding a liquid region to a portion of a bottom surface of a vapor-permeable membrane;   coupling a bottom surface surrounding a vapor region to a portion of a top surface of the vapor-permeable membrane such that the vapor-permeable membrane is interposed between the liquid region and the vapor region to form a membrane heat sink; and   coupling a top surface of a contact portion to a bottom surface of the liquid region,   wherein the liquid region comprises an inlet port configured to communicate a liquid phase heat exchange fluid into the liquid region,   wherein the vapor region comprises an outlet port configured to communicate a vapor phase heat exchange fluid out of the membrane heat sink, and   wherein the vapor-permeable membrane is configured to allow communication therethrough of the vapor phase heat exchange fluid and disallow communication therethrough of the liquid phase heat exchange fluid.   
     
     
         2 . The method of  claim 1 , wherein a rate of communication of the vapor phase heat exchange fluid through the outlet port and out of the vapor region of the membrane heat sink is based upon a rate of communication of the vapor phase heat exchange fluid through the vapor-permeable membrane from the liquid region to the vapor region. 
     
     
         3 . The method of  claim 2 , wherein a rate of communication of the liquid phase heat exchange fluid through the inlet port and into the liquid region is based on the rate of communication of the vapor phase heat exchange fluid through vapor-permeable membrane from the liquid region to the vapor region. 
     
     
         4 . The method of  claim 3 , wherein the rate of communication of the vapor phase heat exchange fluid through the vapor-permeable membrane from the liquid region into the vapor region is based on a rate at which the liquid phase heat exchange fluid undergoes the phase change to the vapor phase heat exchange fluid. 
     
     
         5 . The method of  claim 4 , wherein the rate at which the liquid phase heat exchange fluid undergoes the phase change to the vapor phase heat exchange fluid is based upon a quantity of the heat absorbed by the liquid phase heat exchange fluid. 
     
     
         6 . The method of  claim 5 , wherein the quantity of the heat absorbed by the liquid phase heat exchange fluid is based upon a quantity of heat communicated through the contact portion. 
     
     
         7 . The method of  claim 6 , wherein the membrane heat sink is further configured, during a first time, to absorb a first quantity of heat emitted by a collocated heat source, causing the liquid phase heat exchange fluid in the liquid region to undergo a phase change to the vapor phase heat exchange fluid at a first rate. 
     
     
         8 . The method of  claim 7 , wherein the volume of the liquid phase heat exchange fluid that undergoes the phase change to the vapor phase heat exchange fluid during the first time is based upon a first quantity of the heat absorbed by the liquid phase heat exchange fluid during the first time. 
     
     
         9 . The method of  claim 8 , wherein the membrane heat sink is further configured, during a second time, to absorb a second quantity of heat emitted by the collocated heat source, causing the liquid phase heat exchange fluid in the liquid region to undergo the phase change to the vapor phase heat exchange fluid at a second rate. 
     
     
         10 . The method of  claim 9 , wherein the volume of the liquid phase heat exchange fluid that undergoes the phase change to the vapor phase heat exchange fluid during the second time is based upon a second quantity of the heat absorbed by the liquid phase heat exchange fluid during the second time. 
     
     
         11 . The method of  claim 1 , wherein the contact portion comprises a tungsten-containing material having a coefficient of thermal expansion below a predetermined threshold. 
     
     
         12 . The method of  claim 11 , wherein the tungsten-containing material comprises a copper-tungsten alloy. 
     
     
         13 . The method of  claim 11 , wherein one or more of: the liquid region, the vapor region, or the vapor-permeable membrane comprises a copper-based material. 
     
     
         14 . The method of  claim 11 , wherein the predetermined threshold for the coefficient of thermal expansion of the tungsten-containing material is between about 4.0×10 −6  K −1  and about 10×10 −6  K −1 . 
     
     
         15 . The method of  claim 11 , wherein the tungsten-containing material has:
 a density of between about 15,000 kg/m 3  and about 18,000 kg/m 3 ,   a Young's modulus of between about 200 GPa and about 400 GPa,   a thermal conductivity of between about 100 W/m·K and about 300 W/m·K, and   a specific heat capacity of between about 100 J/kg·K and about 300 J/kg·K.   
     
     
         16 . The method of  claim 11 , wherein the tungsten-containing material has a tungsten concentration between about 0.5 wt. % and about 20 wt. %. 
     
     
         17 . A method of forming a membrane heat sink, the method comprising:
 coupling a liquid chamber to a vapor-permeable membrane on a first side, the liquid chamber being configured to receive and retain therein a liquid phase heat exchange fluid;   coupling a vapor chamber to the vapor permeable membrane on a second side opposite the first side; and   coupling a tungsten-containing contact plate to the liquid chamber on a side opposite the vapor-permeable membrane, the tungsten-containing contact plate having a coefficient of thermal expansion below a predetermined threshold, the tungsten-containing contact plate being configured to communicate heat through the tungsten-containing contact plate and into the liquid chamber when the membrane heat sink is collocated with a heat source emitting the heat,   wherein the liquid phase heat exchange fluid in the liquid chamber is configured to absorb the heat emitted by the heat source and communicated through the tungsten-containing contact plate and into the liquid chamber such that at least a portion of the liquid phase heat exchange fluid experiences a phase change to form the vapor phase heat exchange fluid, and   wherein the vapor-permeable membrane is configured to allow the vapor phase heat exchange fluid formed in the liquid chamber to be communicated through the vapor-permeable membrane and into the vapor chamber while disallowing a remaining portion of the liquid phase heat exchange fluid in the liquid chamber from being communicated through the vapor-permeable membrane and into the vapor chamber.   
     
     
         18 . The method of  claim 17 , further comprising:
 soldering a bottom surface of the tungsten-containing contact plate to a top portion of the heat source.   
     
     
         19 . A method comprising:
 coupling a top surface surrounding a liquid region to a portion of a bottom surface of a vapor-permeable membrane;   coupling a bottom surface surrounding a vapor region to a portion of a top surface of the vapor-permeable membrane such that the vapor-permeable membrane is interposed between the liquid region and the vapor region to form a membrane heat sink; and   coupling a top surface of a contact plate to a bottom surface of the liquid region,   wherein the contact portion comprises a tungsten-containing material having a coefficient of thermal expansion below a predetermined threshold,   wherein the liquid region comprises an inlet port configured to communicate a liquid phase heat exchange fluid into the liquid region,   wherein the vapor region comprises an outlet port configured to communicate a vapor phase heat exchange fluid out of the membrane heat sink,   wherein the vapor-permeable membrane is configured to allow communication therethrough of the vapor phase heat exchange fluid and disallow communication therethrough of the liquid phase heat exchange fluid,   wherein a rate of communication of the vapor phase heat exchange fluid through the outlet port and out of the vapor region of the membrane heat sink is based upon a rate of communication of the vapor phase heat exchange fluid through the vapor-permeable membrane from the liquid region to the vapor region,   wherein a rate of communication of the liquid phase heat exchange fluid through the inlet port and into the liquid region is based on the rate of communication of the vapor phase heat exchange fluid through vapor-permeable membrane from the liquid region to the vapor region,   wherein the rate of communication of the vapor phase heat exchange fluid through the vapor-permeable membrane from the liquid region into the vapor region is based on a rate at which the liquid phase heat exchange fluid undergoes the phase change to the vapor phase heat exchange fluid,   wherein the rate at which the liquid phase heat exchange fluid undergoes the phase change to the vapor phase heat exchange fluid is based upon a quantity of the heat absorbed by the liquid phase heat exchange fluid, and   wherein the quantity of the heat absorbed by the liquid phase heat exchange fluid is based upon a quantity of heat communicated through the contact plate.   
     
     
         20 . The method of  claim 19 , further comprising:
 disposing a volume of a fluidic solder between a bottom surface of the contact portion and a top portion of the collocated heat source; and   allowing the fluidic solder to cool and harden to couple the contact portion to the collocated heat source.